tbuckley/cabot-search huggingface dataset:
Abstract P3036: Circular RNA Decoys Targeting MiR-146a As A Promising Therapeutic Strategy To Improve Vascular Regeneration
Authors: Solveig Boettcher, Katrin Kalies, Kai Knoepp, Jochen Dutzmann, Stefan Huettelmaier, Daniel Sedding
Journal: Circulation Research (2023)

Heart failure and cardiac remodeling following myocardial infarction (MI) depend on capillary density and neovascularization. MicroRNAs (miRNAs), which are small non-coding RNAs that modulate gene expression, play a major role in the pathogenesis of these conditions. Inhibition of these pathways through miRNA sponges, such as antagomiRs or circular decoys (circRNAs), might represent a therapeutic approach for MI. Here, we evaluate the role of miR-146a and present a promising treatment strategy using synthetically designed circular decoys. miRNA-146a expression was analyzed in human vascular cells and mice tissue following either myocardial infarction or hind limb ischemia. CircRNAs were synthetically designed and evaluated. Methods to characterize the effect of inhibition of miR-146a included the quantification of the target gene and protein expression and analysis of cellular functions.miR-146a was significantly upregulated in vitro in senescent cells ( P &lt;0.05) and in vivo in the ischemic myocardium following ligation of the LAD ( P &lt;0.001) in C57BL/6 mice. A circular RNA decoy targeting miR-146a was successfully designed and transfected into vascular cells in vitro . The following analysis showed a significant target upregulation for NOX4, KLF4, and TRAF6 ( P &lt;0.001) after circRNA transfection, also compared to antagomiR transfected cells. Functional analysis revealed improved migration and proliferation capacity in vascular endothelial cells ( P &lt;0.05). First results indicate that inhibition of the upregulation of endothelial miR-146a in mice results in significantly enhanced angiogenesis and revascularization ( P &lt;0.05) accompanied by a significantly reduced myocardial infarct size ( P &lt;0.01) and preserved cardiac function post-MI ( P &lt;0.01). In summary, we could identify miR-146a as a critical regulator of angiogenesis and vascular regeneration, and present a first strategy for angiogenic therapy of ischemic diseases. However, in vitro analysis showed a higher efficiency of circRNAs in the context of inhibiting miR-146a functions in vascular cells. CircRNAs are more stable and more efficient when transfected, compared to antagomiRs, and might be a better alternative and a realistic approach for future clinical studies.
Abstract P2028: Uncoupling Endothelial Trpv4 Mechanotransduction Attenuates Pressure Overload-induced Cardiac Hypertrophy Via Rho/yap/vegfr2 Mediated Coronary Cngiogenesis
Authors: Charles K Thodeti, Ravi K Adapala, Venkatesh Katari, Vahagn A Ohanyan, Sailaja M Paruchuri
Journal: Circulation Research (2023)

Left ventricular hypertrophy (LVH) is a bipolar response, starting as an adaptive response to the hemodynamic challenge, but over time progressing towards a maladaptive pathology with a loss of ventricular function. Despite the profound influence on cardiac function, the mechanotransduction mechanisms that regulate myocardial angiogenesis, leading to heart failure, are not well known. Here, we demonstrate that endothelial-specific deletion of mechanosensitive ion channel TRPV4 preserved cardiac function and structure and reduced fibrosis via increased capillary density compared to WT mice, 28 days post-transverse aortic constriction (TAC). Interestingly, comprehensive RNA sequencing analysis revealed an upregulation of pro-angiogenic factors (FGF2, NOS3, and VEGFα) in TRPV4 ECKO hearts after TAC compared to TRPV4 lox/lox . Further, an increased expression of VEGFR2 and activation of the YAP pathway was observed in TRPV4 ECKO hearts. Mechanistically, we found that downregulation of TRPV4 in human ECs induced matrix stiffness-dependent activation of YAP and VEGFR2 via the Rho/Rho kinase/LATS pathway. Our results thus suggest that endothelial TRPV4 acts as a mechanical break for coronary angiogenesis, and uncoupling TRPV4 mechanotransduction attenuates pathological cardiac hypertrophy by enhancing coronary angiogenesis.
Abstract P2072: Chronic Treatment With An Androgen Receptor Antagonist Promotes Maladaptive Structural And Functional Cardiac Remodeling In Aging Male Mice
Authors: Shubham Banga, Susan E Howlett
Journal: Circulation Research (2023)

Testosterone levels decrease with age in men, while the risk for cardiovascular diseases (CVD) increases dramatically. Indeed, low circulating testosterone levels in men are associated with diseases such as heart failure. Testosterone exerts its effects via androgen receptors, which are even present in the heart. In addition, androgen receptor antagonists are used to treat prostate cancer in older men who may also have CVD. We investigated the effects of the androgen receptor antagonist flutamide on cardiac structure and function in aged mice. Twenty-month-old male C57BL/6 mice were treated with flutamide for 90 days (slow-release pellet implant; ~20mg/kg/day). In-vivo heart structure/function was assessed using echocardiography and then hearts were Langendorff-perfused to assess load-independent ventricular function ex-vivo . Androgen receptor blockade via flutamide caused maladaptive ventricular remodeling. In-vivo studies showed that flutamide-treated mouse hearts had smaller left ventricular inner diameters when compared to vehicle-treated mice ( e.g. , diastolic: 4.7 ± 0.1 vs. 4.4 ± 0.1 mm; p=0.01; n=8,7). Flutamide also caused left ventricular (LV) atrophy with thinner posterior walls (0.91 ± 0.07 vs. 0.74 ± 0.04 mm; p=0.05) and reduced LV mass when compared to vehicle controls (140 ± 12 vs. 105 ± 6 mg; p=0.03). Ex-vivo functional assessment showed a marked reduction in LV developed pressure in the flutamide-treated mice (111 ± 11 vs. 71 ± 3 mmHg; p&lt;0.01). These mice also had significantly slower rates of LV pressure rise (+dP/dT=2219 ± 263 vs. 1406 ± 95 mmHg/s; p&lt;0.01) as well as LV pressure decay (-dP/dT=-1975 ± 263 vs. -1327 ± 132 mmHg/s; p=0.04). This indicates that flutamide-treated mice had defects in both systolic and diastolic cardiac function. These results demonstrate that suppressing the effects of testosterone by blocking androgen receptors promotes maladaptive structural remodeling of the left ventricle and promotes systolic and diastolic dysfunction in hearts from aged male mice. This study suggests that chronic treatment with androgen receptor antagonists may induce cardiac dysfunction in older men, which has implications for individuals taking these medications for prostate cancer treatment.
Abstract P3150: Extracellular Vesicles From Endothelial Progenitor Cells Limit The Development Of Ventricular Dysfunction In A Mouse Model Of Myocardial Infarction
Authors: Ana Paula V Dantas, Joaquim Bobi, IOLANDA LAZARO, Heleen M Van Beusekom, Alarcon Francisco, Alarcon Francisco, José Tomas Ortiz, Merce Roque, Manel Sabate, Salvatore Brugaletta
Journal: Circulation Research (2023)

After myocardial infarction (MI), angiogenesis in the ischemic myocardium is essential for an optimal reparative process to limit the development of ventricular dysfunction. Cell-derived extracellular vehicles (EVs) are emerging as the next-generation strategy in tissue engineering. In this study, we aimed to determine the role of EVs derived from endothelial progenitor cells (EPC) in cardiac function post-MI. EVs were purified from the supernatant of EPC by density gradient centrifugation. MI was induced in C57BL/6 mice (n=23) by left coronary artery ligation and confirmed by EKG. Mice were randomized to receive purified EVs (n=10) or saline (n=10) in two zones of the myocardium, peri-ischemic and central ischemia zones, followed by weekly I.P. injection of EVs or saline for six weeks. Three mice underwent sham surgical procedures without coronary artery ligation. Cardiac magnetic resonance at the end of the follow-up showed significant impairment of left ventricle (LV) performance in the saline group, which was better preserved in mice treated with EVs (Fig 1) . Histological analysis in the LV showed increased collagen deposition in both MI groups (Fig 2A) . However, capillary density decreased more pronouncedly in the saline than in the EV group (Fig 2B) . Quantitative mRNA array revealed a differential relative mRNA expression in the EV group compared to saline (Fig 3) . The administration of EPC-derived EVs has a modest effect on preventing the development of LV adverse remodeling after ischemia, as it limits LV dilation at the long term in a mouse model of chronic MI.Funding: ISCIII (PI19/00264, SEC/FECINV- BAS 20/012)
Abstract P1140: Acute Mechanosensitive Adaptation To Phenylephrine In Cardiomyocytes And Fibroblasts
Authors: Todd H Kimball, Tatiana Gromova, Douglas Chapski, Thomas M Vondriska
Journal: Circulation Research (2023)

Mechanosensitive pathways are fine tuned to the physiological environment of the cell. Adrenergic stimulation induces cell type specific responses in the heart, including cardiomyocyte hypertrophy and fibroblast proliferation. We hypothesized acute induction of hypertrophy by phenylephrine (PHE) would activate mechanosensitive pathways in fibroblasts and myocytes, revealing novel molecular features of early hypertrophic adaptation. Male mice were subcutaneously injected with 20 mg/kg of PHE or PBS every other day for one week. Echocardiography revealed significant cardiac hypertrophy with increased ejection fraction (72.45% + 6.15 PHE v 56.32 + 5.32 PBS, p&lt;0.0001) and LV wall thickness (2.25 mm + 0.29 PHE v 1.62 + 0.13 PBS, p&lt;0.0001), along with diastolic impairment, as measured by elevated E/e’ ratio (37.25 + 7.29 PHE v 23.67 + 3.62 PBS, p&lt;0.0001). Interestingly, histological analysis showed increased fibrotic deposition and cardiomyocyte cross-sectional area was preferential increased in fibrotic areas (265.5 um 2 + 67.5 PHE fibrotic v 195.1 + 47.46 PHE non-fibrotic v 165.6 + 46.96 PBS). While cardiac fibroblasts from PHE-treated animals did not show alpha smooth muscle actin staining, a traditional marker for activated myofibroblasts, fibroblasts from PHE-treated mice showed increased f-actin stress fibers and nuclear localization of Mrtfa, a mechanosensitive transcriptional coactivator. We performed RNA-seq on isolated cardiomyocytes, demonstrating activation of myocyte-specific responses to increased pressure ( Des, Nppa ), as well as activation of fibrotic genes ( Tgfbr1, Tgfbr2, Tgfb2 ) in myocytes . We sought to investigate mechanosensitive pathways initiated by PHE treatment in cardiomyocytes and identified transcriptional changes in Ankrd1, a Titin binding protein which translocates to the nucleus upon stress. We demonstrate a PHE induced increase in Ankrd1 protein expression and nuclear localization (nuclear area occupancy, as measured by microscopy, 17.04% + 8.76 PHE v 11.91% + 9.134 PBS, p=0.002) in cardiomyocytes. Together these findings demonstrate distinct acute phenotyptic adaptation to adrenergic stress in myocytes and fibroblasts, revealing cell type-specific mechanosensitive signaling mechanisms.
Abstract P3042: Cardiomyocyte MicroRNA-125a-5p Plays A Vital Protective Role In Myocardial Infarction And Directly Represses Proapoptotic GTP-Cyclohydrolase I Feedback Regulator
Authors: Taiki Hayasaka, Marisa Sepulveda, Il-man Kim
Journal: Circulation Research (2023)

Background: We reported that microRNA-125a-5p (miR-125a) is activated by β-blocker carvedilol acting through β-arrestin1-mediated β1-adrenergic receptor (receptor found mainly in cardiomyocytes [CMs]) signaling (Figure A). GTP cyclohydrolase I feedback regulator (GCHFR) inhibits tetrahydrobiopterin which is protective in myocardial infarction (MI). Despite these findings, the roles of miR-125a and GCHFR in MI and their mechanisms of actions remain elusive. Here, we hypothesize that miR-125a in CMs plays a protective role in MI in part by repressing GCHFR, a novel target of miR-125a. Methods and Results: Fractionation of cardiac cell types isolated from mouse hearts reveals that miR-125a expression is higher in CMs than other cells. Using cultured CM and in vivo approaches, we show that miR-125a is an ischemic stress-responsive protector against CM apoptosis. CMs lacking miR-125a exhibit an increased sensitivity to apoptosis, whereas CMs overexpressing miR-125a have increased phospho-AKT prosurvival signaling. MiR-125a is downregulated in failing hearts, and miR-125a overexpression protects mouse hearts against MI. Systemic deletion of miR-125a in mice worsens maladaptive post-MI remodeling. Genome-wide profiling in miR-125a KO mouse hearts identifies GCHFR as a novel target of miR-125a. Mechanistically, protective roles of miR-125a in CMs are in part attributed to the direct and functional repression of proapoptotic GCHFR. Last, novel conditional CM-specific miR-125a KO in mice exacerbates maladaptive cardiac remodeling after MI (Figure B). Conclusions: Our findings suggest a crucial role for the miR-125a/GCHFR axis in regulating CM survival post-MI.
Abstract P3171: Tubular Mitochondria Dysfunction Aki Induces Cardiac Malfunction In Cardiorenal Syndrome Type 3
Authors: Hugo Y Lin
Journal: Circulation Research (2023)

Cardiorenal syndrome type 3 (CRS 3) occurs when an acute kidney injury (AKI) leads to the development of cardiac dysfunction. It is associated with significant morbidity and mortality and is becoming increasingly prevalent. Mitochondrial dysfunction in renal tubular cells has been proposed as a critical regulator of AKI, but the exact mechanism of renal tubular mitochondrial dysfunction AKI-induced CRS 3 is still unclear. This study aims to characterize kidney and heart tissue injuries after AKI induced by maleic acid (MA). In an in vivo model, MA was used to induce AKI in C57BL/6 mice, and in an in vitro model, human proximal tubular epithelial cells (HK-2) were treated with MA. Our results showed that MA-induced AKI exacerbated renal tubular injury, increased the expression of renal injury molecule-1 (KIM-1), and caused apoptosis of renal tubular cells. At the cellular level, mitochondrial dysfunction was associated with increased mitochondrial reactive oxygen species (ROS), decreased coupling of mitochondrial respiration with decreased electron transport capacity, and reduced production of ATP. Transmission electron microscopy (TEM) examination revealed that mitochondrial cristae formation was defective in MA-induced AKI. Gene expression analysis revealed significantly lower ATPase6 levels and protein analysis confirmed that renal mitochondrial proteins of ATP subunits 5A1 and 5C1 were reduced considerably. The increase of NF-kB of the cardiac endothelial cell was observed with immunohistochemistry staining. Our study demonstrated that tubular mitochondrial dysfunction resulting from altered expression of ATP synthase is associated with AKI-induced type 3 cardiorenal syndrome, providing a potential novel target for developing new strategies for preventing and treating CRS3.
Abstract P2115: (2R,6R)-Hydroxynorketamine Prevents Myocardial Ischemia Reperfusion Injury By Regulating Immune And Inflammatory Response
Authors: Baihe Chen, Tao Luo, Masafumi Kitakaze
Journal: Circulation Research (2023)

Background: The ketamine metabolite 2R,6R-hydroxynorketamine (HNK) has recently attracted increasing attention by its potential as a novel fast-acting antidepressant candidate to treat depression. HNK has anti-inflammatory properties which contribute to its protective effects against ischemia and reperfusion (I/R) injury. However, whether HNK produces beneficial effects on myocardial I/R injury has not been elucidated yet. Here we tested the hypothesis that HNK might protects the heart from myocardial I/R injury by limiting myocardial inflammation. Methods and Results: Twelve male C57BL/6J mice (8-10 weeks old, 20-25 g) were used to produce acute myocardial I/R (30 min/24 h) by micro-surgery. Mice were divided into four groups: Sham, HNK+Sham, I/R, HNK+I/R. A single-dose of HNK (30 mg/kg) was intraperitoneally injected one hour before the I/R. Echocardiographic imaging and TTC staining showed that HKN administration before myocardial I/R increased fraction shortening by 26.5% and limited infarct size by 40% compared to I/R alone. Proteomics analysis showed HNK caused 81 proteins down-regulated and 18 proteins up-regulated in the left ventricle after I/R (HNK+I/R vs . I/R). The gene name of the top 5 down-regulated proteins are Ighg2b, Igkv17-121, Igkc, Igtp and Cd68. The go enrichment analysis showed that HNK in the I/R group could modulate immune response via downregulating signal transducer and activation of transcription 1 and 2 (STAT1 and STAT2) and type 1 interferon pathway. The KEGG enrichment analysis showed that HNK affected antigen processing and presentation via down-regulating beta-2-microglobulin, TAPBP and TAP1/2. Cytokine analysis showed that HNK attenuated the increased tissue levels of TNF-alpha, IL-1 beta, CTnI and BNP induced by I/R. HNK also significantly decreased I/R induced-neutrophil infiltration, apoptosis and oxidative stress in the myocardium as detected by Ly6G staining, tunel staining and DHE probe staining. Conclusion: We demonstrated for the first time the administration of HNK regulates immune response through STAT1 and STAT2 and type 1 interferon pathway in the heart, leading to the cardioprotection against I/R injury. The use of HNK may become an immunomodulatory therapy for the ischemic heart disease.
Abstract P2087: Contributions Of A Glycolytic Switch To Hfpef In Two Mouse Models
Authors: Ali Kamiar, Monique Williams, Jose Manuel Condor, Monica Anne Rasmussen, Qusai Alitter, Keith A Webster, Katarzyna Kazmierczak, Jingsheng Liang, Danuta Szczesna-Cordary, Lina A Shehadeh
Journal: Circulation Research (2023)

Background: Switching from fatty acid oxidation to less efficient but more expeditious glycolysis is associated with oncometabolism and more recently cardiac hypertrophy. We hypothesized that such a switch drives HFpEF in two diverse mouse models. Method: WT/129J mice at age 4-weeks were subjected to biweekly p407 i.p. injections and a single i.v. injection of AAV9-cTnT-LDLR. A separate group of injected mice were fed a diet supplemented with alpha-ketoglutarate (2% aKG) at onset. 4-week-old Alport mice received either aKG diet or normal chow. Glucose uptake was measured by whole-body PET-CT imaging of 18F-FDG in four groups: (1) untreated mice (n=5), (2) LDLR/P407 mice at 1, 2, 4, 7 (n = 3) and 8 weeks treatment (n=5), (3) LDLR/P407 + aKG mice at 4-weeks treatment (n=5), and (4) 9-12-weeks Alport mice (n=5). Echocardiography was performed on untreated mice (n=14), 4-week LDLR/P407 treatment mice (n=17), and 4-week LDLR/P407 + aKG treatment mice (n=5). Mechanical and energetic measurements on skinned cardiac pupillary muscles were performed on late-stage Alport (n=8), 8-week-treated LDLR/P407 (n=9), 4-week-treated LDR/P407 + aKG mice (n=2), and untreated controls (n=8). Survival of LDLR/P407 (n=13), LDLR/P407/aKG (n=8) and control groups were recorded. Results: PET-CT scans showed increased cardiac glucose uptake in Alport (FC=3, p&lt; 0.05) and LDLR/P407 mice at 1, 2, 4 (FC = 2, p&lt;0.05), and 8 weeks (FC=3.2, p&lt;0.001). aKG diet increased cardiac glucose uptake in LDLR/P407 at 4 weeks compared to normal chow (FC=2.15, p&lt;0.05). Doppler and echocardiography showed worse diastolic dysfunction (E/E’) (FC = 1.8, P&lt;.05) in LDLR/P407 αKG mice at 4-weeks versus control chow. Alport hearts favored a DRX state (FC= 1.52, p &lt;.0001) while 8-week-LDLR/P407 hearts favored SRX (FC=1.1, p&lt; 0.05). The SRX state was exacerbated by aKG diet in 4-week-LDLR/P407 relative to normal chow. aKG diet significantly shortened life spans of LDLR/P407 mice (p&lt;0.001). Conclusion: The results support roles for oncometabolism in promoting HF and sudden death in Alport and LDLR/P407 mice, effects that were exacerbated by an aKG supplement, possibly via enhanced hypertrophic growth. Results suggest an αKGDH-dependent and phenotype-dependent redistribution of myosin energetic states.
Abstract P3183: Cardiac Troponin I Directly Binds Mitochondrial Proteins And Inhibits Mitochondrial Functions
Authors: Aly Elezaby, Amanda J Lin, Vijith Vijayan, Suman Pokhrel, Luiz Bechara, Nicolai Ostberg, Bruno B Queliconi, Juliane Campos, Julio Ferreira, Bereketeab Haileselassie, Daria Mochly-Rosen
Journal: Circulation Research (2023)

The heart relies on mitochondria for its extensive energetic demands, and some cytoskeletal elements can regulate mitochondrial function. Cardiac troponin I (cTnI) is a structural protein involved in sarcomeric contraction. Here we demonstrate that some cTnI localizes to mitochondria, inhibits mitochondrial functions, and increases opening of the mitochondrial permeability transition pore under oxidative stress. Purified cTnI directly binds immune-captured ATP synthase in saturable fashion and doubles "reverse" F 1 F 0 -ATPase activity in vitro , whereas skeletal troponin I (ssTnI) does not. Relevant to human disease, several pathogenic variants of cTnI associated with hypertrophic cardiomyopathy do not increase F 1 F 0 -ATPase activity. Using a rational search, we identified the d subunit of ATP synthase as a potential cTnI-binding partner, and a ten-amino acid peptide inhibitor of cTnI’s interaction with ATP synthase, peptide P888, inhibited cTnI binding to ATP synthase and abolished the cTnI-induced increase in ATPase activity. P888 treatment greatly reduced cardiac LDH release and improved fractional shortening in vivo after transient coronary artery occlusion in rats, indicating that mitochondrial cTnI exacerbates cardiac ischemia-reperfusion injury. We explore the mechanisms governing cTnI’s mitochondrial localization and additional mitochondrial binding partners for cTnI. Together, our studies suggest that mitochondria-associated cTnI inhibits ATP synthase under basal conditions. Preventing cTnI from binding to ATP synthase during cardiac ischemia may increase the reservoir of functional mitochondria to mitigate post-ischemic cardiac injury. We also suggest that cTnI has additional roles in regulating mitochondrial functions. Finally, pathogenic cTnI mutations associated with hypertrophic cardiomyopathy do not affect ATP synthase activity, suggesting a potential mechanism that contributes to the diverse pathologies associated with these mutations.